In an experiment, a researcher manipulates and changes some conditions that participants are exposed to in order to observe the effects on some mental process or behavioral outcome.
The researcher also keeps other variables constant, to control irrelevant factors.
To conduct an experiment, you must first identify the dependent variable, the independent variable, the experimental group, and the control group.
Once this is complete, you must think of a way to operationally define the variables.
An operational definition states a theoretical construct in terms of concrete, observable procedures.
In order to be as specific as possible, the variables need to be defined very concretely.
Researchers could potentially operationally define things differently.
The researchers perspective and judgment shape the research.
Random assignment helps control for any individual differences between participants and helps reduce bias.
Variables Worksheet
Name: Aubrie Marshall
Please identify the independent variables, dependent variables, control variables and suggest possible extraneous or confounding variables for each of the following problem students.
1. This study will investigate the relationship between parental drug addition and the incidence of birth defects in infants.
- Independent: Parental drug addiction (cause)
- Dependent: Incidence of birth defects in infants (effect)
- Extraneous: Type of drug used by parent, gender, economic class (not accounted for in study)
2. The purpose of this research is to study the effects of repetition on long term and short term memory of adult college students.
- Independent: long term and short term memory of adult college students
- Dependent: effects of repetition
- Extraneous: what their grades are, gender, and age.
3. The purpose of this study is to determine the effect of positive reinforcement on the self concept levels of male and female fifth grade students.
- Independent: self concept levels of male and female fifth grade students
- Dependent: effect of positive reinforcement
- Extraneous: the class or teacher that gives the student positive reinforcement
4. This study will compare the differences between counselors and non-counselors on a measure of self-disclosure.
- Independent: differences between counselors and non-counselors
- Dependent: self-disclosure
- Extraneous: gender and age of counselors or non-counselors
5. This research investigates the relative effectiveness of two types of incentives, token and praise, on math achievement in high school sophomores. Gender differences are also analyzed.
- Independent: math achievement in high school sophomores
- Dependent: gender, praise, & token
- Extraneous: what the sophomores receiving token and praise are like, who is giving the token & praise
6. This study will study dropout rates of male students compared to female students.
Variable Notes
Variables Worksheet
Name: Aubrie Marshall
Please identify the independent variables, dependent variables, control variables and suggest possible extraneous or confounding variables for each of the following problem students.
1. This study will investigate the relationship between parental drug addition and the incidence of birth defects in infants.
- Independent: Parental drug addiction (cause)
- Dependent: Incidence of birth defects in infants (effect)
- Extraneous: Type of drug used by parent, gender, economic class (not accounted for in study)
2. The purpose of this research is to study the effects of repetition on long term and short term memory of adult college students.
- Independent: long term and short term memory of adult college students
- Dependent: effects of repetition
- Extraneous: what their grades are, gender, and age.
3. The purpose of this study is to determine the effect of positive reinforcement on the self concept levels of male and female fifth grade students.
- Independent: self concept levels of male and female fifth grade students
- Dependent: effect of positive reinforcement
- Extraneous: the class or teacher that gives the student positive reinforcement
4. This study will compare the differences between counselors and non-counselors on a measure of self-disclosure.
- Independent: differences between counselors and non-counselors
- Dependent: self-disclosure
- Extraneous: gender and age of counselors or non-counselors
5. This research investigates the relative effectiveness of two types of incentives, token and praise, on math achievement in high school sophomores. Gender differences are also analyzed.
- Independent: math achievement in high school sophomores
- Dependent: gender, praise, & token
- Extraneous: what the sophomores receiving token and praise are like, who is giving the token & praise
6. This study will study dropout rates of male students compared to female students.
- Independent: dropout rate
- Dependent: gender, age
- Extraneous: cause of the students dropping out